831
FXAK68 PAFC 230034
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
434 PM AKDT SUN MAR 22 2026
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
A PAIR OF LOWS IN THE GULF WITH THE NORTHERN MOST ONE GRAZING THE
IMMEDIATE COAST WITH SNOW SHOWERS CONTINUES TO DRIFT SOUTHWARD AS
A BROAD, POSITIVELY TILTED UPPER LEVEL TROUGH PROGRESSIVELY DIGS
SOUTH OVER THE GULF. AS THIS HAPPENS TODAY THROUGH TONIGHT, EXPECT
GAP WINDS FOR MANY LOCATIONS TO WEAKEN FOR A TIME AS THE PRESSURE
GRADIENT DECREASES. HOWEVER, A HIGH AMPLITUDE 500 MB RIDGE BUILDS
OVER THE BERING MONDAY MORNING, WHICH WILL AMPLIFY THE UPPER
LEVEL PATTERN AND YIELD A NORTHEASTERLY JET OVER MAINLAND AND
SOUTHCENTRAL ALASKA. WEAK WAVES EMBEDDED WITHIN THIS FLOW WILL
LIKELY CAUSE GAP WINDS TO MARGINALLY TICK BACK UP AGAIN. THE PAST
FEW RUNS OF THE GLOBAL MODELS SHOW WAVES DIGGING A BIT MORE
WESTWARD WITHIN THIS JET AND CLOSER TO THE SOUTHWEST ALASKA
REGION, WHICH COMPLICATES THE WIND FORECAST FOR THE MATANUSKA
VALLEY. THE OVERALL THINKING IS THAT GAP WINDS FOR THE MATANUSKA
VALLEY WILL BEGIN TO INCREASE AGAIN TUESDAY INTO WEDNESDAY, THOUGH
SEEING HIGH WIND CRITERIA AS OF NOW IS OF VERY LOW CONFIDENCE. A
NORTHEAST TO SOUTHWEST ORIENTED TROUGH AND A TEMPERATURE GRADIENT
BETWEEN THE MATANUSKA VALLEY AND THE COPPER RIVER BASIN IS ENOUGH
TO SUGGEST WINDS WILL INCREASE, BUT AGAIN THE LIMITING OR PERHAPS
"MISSING" FACTOR IS SHORTWAVE ENERGY DRIVING DIRECTLY OVER THE
AREA. IN THIS CASE, IF THERE ARE NO CHANGES, THE CORRIDOR OF
STRONGEST WINDS BECAUSE OF THE FLOW ORIENTATION MAY ACTUALLY SHIFT
WEST OF THE USUAL PALMER LOCATION TO MORE SO ACROSS WASILLA. STAY
TUNED AS THIS WILL BE SOMETHING TO WATCH AND FINE TUNE OVER THE
NEXT DAY OR SO. BEYOND WEDNESDAY, THE UPPER LEVEL PATTERN LOOKS
ALMOST STEADY-STATE EXCEPT THE TROUGHING BECOMES MORE BROAD IN
NATURE. THE ONE AND PERHAPS ONLY LOCATION TO WATCH FOR ANY NOTABLE
PRECIPITATION WOULD BE KODIAK ISLAND IN THE EVENT ONE OF THESE
MORE COMPACT GULF LOWS MOVES CLOSER TO THE AREA.
-AM
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(DAYS 1 THROUGH 3: THIS AFTERNOON THROUGH WEDNESDAY EVENING)...
THE WARMING TREND WILL CONTINUE OVER MAINLAND SOUTHWEST ALASKA
THROUGH THE SHORT-TERM PERIOD, ALONG WITH DRY CONDITIONS. THE LOW
IN THE GULF OF ALASKA CONTINUES TO PERSIST AS DOES THE STRONG
RIDGE IN THE CENTRAL BERING SEA. THIS CONFIGURATION, ALLOWS FOR
NORTHERLY FLOW AND DRY AIR TO CONTINUE FLOWING INTO SOUTHWEST.
HOWEVER, THE AIRMASS CONTINUES TO MODIFY IN THE WARMER DIRECTION
WITH THE HEART OF THE COLD AIR NOW WELL TO THE EAST IN
YUKON/NORTHWEST TERRITORIES, CANADA.
GUSTY NORTHERLY GAP WINDS WILL CONTINUE ACROSS THE ALASKA
PENINSULA (AKPEN) THROUGH THE SHORT-TERM AS THE SYNOPTIC PATTERN
PERSISTS AS DISCUSSED ABOVE. SNOW SHOWER ACTIVITY HAS LARGELY BEEN
HELD IN CHECK BY THE LOSS OF COLD AIR ADVECTION AND WEAK FORCING.
A SOMEWHAT STRONGER UPPER-LEVEL DISTURBANCE MOVES SOUTHWARD AND
ACROSS THE AKPEN MONDAY EVENING INTO TUESDAY MORNING WITH SNOW
SHOWER ACTIVITY INCREASING ACROSS THE AKPEN, ESPECIALLY THE
SOUTHERN AKPEN. THERE REMAINS SOME UNCERTAINTY ON HOW LONG SNOW
SHOWERS PERSIST ALONG THE AKPEN AFTER TUESDAY MORNING DUE TO
ADDITIONAL UPPER WAVES MOVING OVERHEAD WITH NOT A LOT OF COLD AIR
ADVECTION PRESENT.
FARTHER OUT WEST, A GALE-FORCE FRONT, ORIGINATING FROM A NORTH
PACIFIC LOW SOUTH OF KAMCHATKA, MOVES INTO THE WESTERN BERING SEA
AND WESTERN ALEUTIANS THE REST OF TODAY THROUGH MONDAY. THE FRONT
AND ITS SOUTHEASTERLY GALE-FORCE WINDS WEAKEN BACK TO SMALL CRAFTS
BY SUNDAY AFTERNOON. LIGHT TO MODERATE RAIN REMAINS OVER SHEMYA
THE REST OF THIS AFTERNOON THROUGH MONDAY MORNING BEFORE THE BEST
MOISTURE AXIS SHIFTS EAST TOWARDS KISKA ISLAND AND AMCHITKA. DUE
TO THE STRENGTH OF THE CENTRAL BERING RIDGE, THE CENTRAL ALEUTIANS
(ADAK/ATKA) LOOK TO REMAIN DRY AS THE FRONT WEAKENS IN PLACE TO
THEIR WEST. ANOTHER FRONT APPROACHES THE WESTERN BERING AND
WESTERN ALEUTIANS BY WEDNESDAY AFTERNOON AND EVENING BRINGING
ANOTHER RAIN AND SOUTHEAST WINDS TO SHEMYA.
.LONG TERM FORECAST (DAYS 4 THROUGH 7: THURSDAY THROUGH
SUNDAY)...
THE START OF THE LONG TERM FORECAST ON THURSDAY IS SIMILAR TO
WHAT HAS BEEN SEEN, TROUGHING OVER SOUTHCENTRAL RIDGING OVER THE
BERING. SURFACE FEATURES IN THE GULF OF ALASKA ARE UNCERTAIN WITH
A LOW POSITIONED SOMEWHERE. DEPENDING ON WHERE IT IS, MORE OR LESS
PRECIPITATION AND WINDS WILL IMPACT THE GULF COAST. REGARDLESS,
INLAND AREAS WILL REMAIN DRIER WITH LIGHTER WINDS. THE PATTERN
REMAINS SIMILAR THROUGH SUNDAY FOR SOUTHCENTRAL, WITH THE LOW
MEANDERING AROUND THE GULF.
SOUTHWEST ALASKA'S PATTERN IS SIMILARLY UNCERTAIN. THE RIDGE IN
THE BERING IS EXPECTED TO GRADUALLY BREAKDOWN THROUGH SUNDAY, WITH
AN UPPER LOW ENCROACHING FROM THE WEST. DEPENDING ON WHICH MODEL
YOU LOOK AT, A FRONT WILL SLOWLY MAKE ITS WAY EASTWARD, BRINGING
GUSTY WINDS AND PRECIPITATION, BUT IT IS VERY UNCERTAIN IF THE
LOW WILL SURVIVE ONCE IT REACHES THE PRIBILOF ISLANDS. SOUTHERLY
FLOW WILL ACCOMPANY THIS FRONT, SO WARM AIR ADVECTION IS ALSO
EXPECTED IN THE BERING. THE SOUTHWEST MAINLAND IS EXPECTED TO
REMAIN UNDER A COLDER AIR MASS, SO TEMPERATURES WILL REMAIN ON THE
COLD SIDE THROUGH SUNDAY.
-JAR
AVIATION
PANC...VFR CONDITIONS AND LIGHT WINDS WILL PERSIST.
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